Austin Harrouff was eating dinner with his father at a restaurant in Jupiter, Florida, before he stormed off at about 8:30 p.m.

According to a police report, his mother, Mina called 911 before midnight Monday, saying: "I don't know how to do this. My son has taken off. It seems like he's a little delusional. He says he feels immortal, like a superhero."

She told the operator that Austin had been "acting strange the last week or so" and claimed he had super powers.

Mina was asked if her 19-year-old son had a drug problem or history of mental illness and she said no.

She said he had no phone and no identification on him when he left the restaurant. Mina added: "I will say the only thing he has on him is a pocketknife switchblade."

The worried mother said she was calling his friends in an attempt to locate her son, but no one had seen him.

The mom's worst fears were realized when cops say he walked four miles before randomly encountering John Stevens, 59, and Michelle Mishconin, 53, who were watching TV in their garage.

Harrouff allegedly beat and stabbed the couple to death. When cops rushed to the victims’ home, they say they found him gnawing on the victim's face.